Stents have been employed, for example, in the urethra, the ureters, the biliary tract, the cervix, the rectum, the esophagus, and blood vessels of mammals to relieve the pathological effects of constrictions or obstructions occurring in these passageways.
Bladder obstruction arising from enlargement of the prostate gland in males is one of the most commonly encountered disorders in urology. The prostate gland lies under the bladder and surrounds the passageway known as the prostatic urethra, which transfers fluids from the bladder to the sphincter and ultimately through the rest of the urethra and outside the body. An enlarged prostate gland constricts the prostatic urethra leading to a condition known as benign prostatic hyperplasia (“BPH”). BPH causes a variety of obstructive symptoms, including urinary hesitancy, straining to void, decreased size and force of the urinary stream, and in extreme cases, complete urinary retention possibly leading to renal failure. A number of other irritating symptoms also may accompany BPH, including urinary frequency and urgency, nocturnal incontinence, and extreme discomfort.